enum OptionKey {
  A,
  B,
  C,
  D
}

enum AttemptStatus {
  IN_PROGRESS,
  SUBMITTED
}

entity Subject {
  name String required minlength(2) maxlength(100),
  description String maxlength(1000),
  active Boolean required
}

entity Question {
  prompt String required minlength(5) maxlength(2000),
  explanation String maxlength(2000),
  active Boolean required
}

entity Choice {
  optionKey OptionKey required,
  content String required maxlength(500),
  displayOrder Integer required min(1) max(4),
  correct Boolean required
}

entity ExamAttempt {
  startedAt Instant required,
  submittedAt Instant,
  status AttemptStatus required,
  score Integer min(0)
}

entity ExamAnswer {
  questionTextSnapshot String required maxlength(2000),
  explanationSnapshot String maxlength(2000),
  selectedOption OptionKey,
  selectedContentSnapshot String maxlength(500),
  correct Boolean,
  awardedPoints Integer min(0)
}

relationship OneToMany {
  Question{choice} to Choice{question required}
  ExamAttempt{answer} to ExamAnswer{attempt required}
}

relationship ManyToOne {
  Question{subject(name) required} to Subject
  ExamAttempt{subject(name) required} to Subject
  ExamAttempt{user(login) required} to User with builtInEntity
  ExamAnswer{question required} to Question
}

dto Subject, Question, Choice, ExamAttempt, ExamAnswer with mapstruct
service Subject, Question, Choice, ExamAttempt, ExamAnswer with serviceClass
paginate Subject, Question, ExamAttempt with pagination